diff options
| -rwxr-xr-x | calculate_average_0xshivamagarwal.sh | 22 | ||||
| -rw-r--r-- | src/main/java/dev/morling/onebrc/CalculateAverage_0xshivamagarwal.java | 137 |
2 files changed, 159 insertions, 0 deletions
diff --git a/calculate_average_0xshivamagarwal.sh b/calculate_average_0xshivamagarwal.sh new file mode 100755 index 0000000..32298fb --- /dev/null +++ b/calculate_average_0xshivamagarwal.sh @@ -0,0 +1,22 @@ +#!/bin/sh +# +# Copyright 2023 The original authors +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +JAVA_OPTS="--enable-preview -XX:+UnlockExperimentalVMOptions -XX:+TrustFinalNonStaticFields -dsa -XX:+UseNUMA" +if [[ ! "$(uname -s)" = "Darwin" ]]; then + JAVA_OPTS="$JAVA_OPTS -XX:+UseTransparentHugePages" +fi +java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_0xshivamagarwal diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_0xshivamagarwal.java b/src/main/java/dev/morling/onebrc/CalculateAverage_0xshivamagarwal.java new file mode 100644 index 0000000..77a04bf --- /dev/null +++ b/src/main/java/dev/morling/onebrc/CalculateAverage_0xshivamagarwal.java @@ -0,0 +1,137 @@ +/* + * Copyright 2023 The original authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package dev.morling.onebrc; + +import static java.lang.foreign.ValueLayout.JAVA_BYTE; +import static java.nio.file.StandardOpenOption.READ; + +import java.io.IOException; +import java.lang.foreign.Arena; +import java.lang.foreign.MemorySegment; +import java.nio.channels.FileChannel; +import java.nio.file.Path; +import java.util.HashMap; +import java.util.Map; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class CalculateAverage_0xshivamagarwal { + private static final Path FILE = Path.of("./measurements.txt"); + private static final byte COLON = ';'; + private static final byte NEW_LINE = '\n'; + private static final byte HYPHEN = '-'; + private static final byte DOT = '.'; + private static final int NO_OF_THREADS = Runtime.getRuntime().availableProcessors(); + + private static long[] mergeFn(final long[] v1, final long[] v2) { + v1[0] = Math.min(v1[0], v2[0]); + v1[1] = Math.max(v1[1], v2[1]); + v1[2] += v2[2]; + v1[3] += v2[3]; + return v1; + } + + private static String toString(final Map.Entry<String, long[]> entry) { + var m = entry.getValue(); + + return entry.getKey() + + '=' + + m[0] / 10.0 + + '/' + + Math.round(1.0 * m[2] / m[3]) / 10.0 + + '/' + + m[1] / 10.0; + } + + private static Map<String, long[]> parseData( + final MemorySegment data, long offset, final long limit) { + var map = new HashMap<String, long[]>(10000, 1); + var sep = false; + var neg = false; + var key = new byte[100]; + var len = 0; + var val = 0; + + while (offset < limit) { + var b = data.get(JAVA_BYTE, offset++); + if (sep) { + if (b == NEW_LINE) { + val = neg ? -val : val; + map.merge( + new String(key, 0, len), + new long[]{ val, val, val, 1 }, + CalculateAverage_0xshivamagarwal::mergeFn); + sep = false; + neg = false; + len = 0; + val = 0; + } + else if (b == HYPHEN) { + neg = true; + } + else if (b != DOT) { + val = val * 10 + (b - 48); + } + } + else if (b == COLON) { + sep = true; + } + else { + key[len++] = b; + } + } + + return map; + } + + public static void main(String[] args) throws IOException { + final String result; + + try (var channel = FileChannel.open(FILE, READ); + var arena = Arena.ofShared()) { + var data = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size(), arena); + var chunkSize = data.byteSize() / NO_OF_THREADS; + var chunks = new long[NO_OF_THREADS + 1]; + chunks[NO_OF_THREADS] = data.byteSize(); + + for (int i = 1; i < NO_OF_THREADS; ++i) { + var chunkPos = i * chunkSize; + + while (data.get(JAVA_BYTE, chunkPos++) != NEW_LINE) { + } + + chunks[i] = chunkPos; + } + + result = IntStream.range(0, NO_OF_THREADS) + .mapToObj(i -> parseData(data, chunks[i], chunks[i + 1])) + .parallel() + .reduce( + (m1, m2) -> { + m2.forEach((k, v) -> m1.merge(k, v, CalculateAverage_0xshivamagarwal::mergeFn)); + return m1; + }) + .map( + map -> map.entrySet().parallelStream() + .sorted(Map.Entry.comparingByKey()) + .map(CalculateAverage_0xshivamagarwal::toString) + .collect(Collectors.joining(", ", "{", "}"))) + .orElse(null); + } + + System.out.println(result); + } +} |